[OE-core] Backport gcc7 fixes for armv5e [ARM] PR 82445

[Andre McCurdy]

On Tue, Nov 7, 2017 at 3:00 PM, Andrea Adami <andrea.adami at gmail.com> wrote:
> On Fri, Nov 3, 2017 at 4:10 PM, akuster808 <akuster808 at gmail.com> wrote:
>> On 11/02/2017 01:46 AM, Andrea Adami wrote:
>>>
>>> the gcc7 shipped with rocko produces unbootable kernels on armv5e [1].
>>> Bug was fixed recently, apparently in revision 253892 [2]
>> If you have  a test case ie qemu settings, I can open a bug and handle
>> it that way too
>>
>
> Armin,
>
> once I saw the kernel was not booting on real device I wondered about
> gcc and did a build for qemuarm/arm926js.
> This one was booting fine on qemu.
>
> I then beated OE's qemu to run for my spitz device (spitz is supported
> by qemu but lacks some variables needed by the script) and with my
> surprise it was booting...
>
> So no, qemu is not a valid testbench for this specific issue :)

Googling for "qemu arm alignment faults" brings up a few links which
suggest that to be true - qemu doesn't seem to be strict about
emulating ARM alignment faults. The links are a little old though, so
maybe newer qemu versions can configured to be stricter.

  https://stackoverflow.com/questions/19990756/aligment-faults-ignored-on-armv5te-in-qemu
  https://patchwork.ozlabs.org/patch/550535/